When drilling wells of this type, it may be desirable to leave the well for a shorter or longer time. This may e.g. be the case for exploration wells or test wells, but may also be the case for production wells drilled by means of a floating drilling vessel before a more or less permanent production platform can be placed on the site. Under such circumstances, months or years may pass from finished drilling or testing of the well to reopening of the well for further use.
In order to protect the well heads of such wells in the meantime, it may be advantageous to cover these by means of a suitable cap or the like in order to prevent them from being damaged by fishing tackle or other equipment being dragged along the sea floor. However, such a protection cap would be excessively large if it also would have to cover the guide posts on the guide base. It would therefore be advantageous if the guide posts could be made removable so that they may be removed when the protection cap has been brought in place and later be installed when the well is to be reopened.
Removable guide posts are previously known, e.g. from U.S. Pat. No. 4,439,068. The purpose of these previously known posts has often been to permit replacement if they for some reason or other should have been damaged in use. For this purpose, the guide posts usually have a connecting system, with a female element in the form of a socket or sleeve arranged on the guide base and a male element or spigot on the lower end of the guide post itself fitting into the socket. In order to hold the spigot in place in the socket, engagement means are usually arranged, e.g. in the form of wedges, which are movable into engagement with suitable slots for locking the guide post to the guide base.
Such previously known systems are relatively complicated and comprise many movable parts which are arranged with relatively small clearance in order to function according to their purpose. These factors reduce the reliability i.a. because sand and other fine particles that may be stirred up from the bottom can penetrate between the parts and cause friction or jamming. Furthermore, these systems are not very suitable for applications where the guide posts stay dismounted for longer periods. Under such circumstances drifting particles and marine growth may deposit in the sockets, and even by means of a diver it would be difficult to clean the socket to a sufficient extent for it to receive the spigot on the guide post. Such cleaning would be almost impossible if, instead of divers, it would be necessary to use a remotely operated underwater vehicle, because its external manipulators would not get sufficient access to the narrow space constituted by the socket.